This invention relates to a composite material consisting of a non-metallic portion and a metallic portion. With the discovery of ceramic superconducting material and particularly with the discovery of ceramic superconducting materials having T.sub.c s higher than the temperature of liquid nitrogen, a flurry of activity has occurred in the scientific community relating to these ceramic materials as well as newly discovered materials and the potential uses for them. Even with elevated T.sub.c s, at the present time the state of the superconductor art is such that superconducting materials must be cooled to a significant extent before the onset of superconducting properties, that is the point at which the electrical resistance becomes zero there is complete diamagnetism. Taking into account the requirement of significant cooling, there will be difficulties in adhering superconducting ceramics to metal substrates due to the differences in the coefficients of expansion of the variant materials as well as thermal shocks created during repetitive thermal cycling between superconducting temperatures and ambient or elevated temperatures.
Various superconductor systems have been investigated including the 1-2-3 system and the 2-2-1-2 system, these respectively being the Y-Ba.sub.2 -Cu.sub.3 -O.sub.x system and the Bi.sub.2 -Sr.sub.2 -Ca-Cu .sub.2 -O.sub.x systems. Both of these superconductors ceramics and the bonding of ceramics to metals has heretofore been difficult, if not impossible.
By accident it has been found that ceramics will bond to certain metal alloys and this serendipitous discovery is the basis for the invention.
Accordingly, it is a principal object of the invention to provide a composite material of a ceramic or glass portion and a metal portion.
Another object of the invention is to provide a method of bonding a metal to a non-metallic such as glass or ceramic.
Another object of the invention is to provide a composite comprising a non-metallic portion and an alloy portion wherein the alloy comprises an alkali metal and a metal which is an electrical conductor and forms an alloy with the alkali metal.
Still another object of the invention is to provide a composite of a non-metallic portion and an alloy portion diffusion bonded thereto, the alloy portion comprised of an alkali metal of Li, Na, K or mixtures thereof and an electrically conductive metal which forms an alloy with the alkali metal.
Another object of the invention is to provide a method of forming a composite of a non-metallic member and metal alloy covering at least a portion of the non-metallic member, comprising providing a non-metallic member having an exposed surface, bonding a metal alloy including one or more of an alkali metal and one or more of a metal selected from the group consisting of Cu, Ag, Al and Au to at least a portion of the exposed surface of the non-metallic member, and thereafter bonding a metal to the metal alloy.
Another object of the invention is to provide a method of forming a composite of a non-metallic portion and metal alloy covering at least a part of the non-metallic portion, comprising providing a non-metallic portion having an exposed surface, providing a metal alloy including one or more of an alkali metal and one or more of an electrically conductive metal which forms an alloy with the alkali metal bonded to at least a part of the non-metallic portion.
A final object of the invention is provide an electrical conductor comprising a plurality of ceramic superconductor members surrounded by an electrically conducting alloy binder containing an alkali metal enclosed by a heat-transfer casing.
The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.